Browsing by Author "Hsu, Tzu Min"

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Enhancing luminescence efficiency of InAs quantum dots at 1.5 mu m using a carrier blocking layer
(2006-07-31)
Hsieh, Tung-Po
;
Chiu, Pei-Chin
;
Chyi, Jen-Inn
;
Chang, Hsiang-Szu
;
Chen, Wen-Yen
The authors report an effective way to enhance the optical efficiency of InAs quantum dots (QDs) on GaAs emitting at the wavelength of 1.5 mu m. It is found that the loss of holes from QDs to their proximity via the high indium composition InGaAs overgrown layer, which is necessary for achieving long wavelength emission, is the origin of photoluminescence intensity degradation at high temperature. Inserting a 4 nm thick Al0.45Ga0.55As layer, acting as a carrier blocking layer, into the GaAs capping matrix can improve the room temperature photoluminescence peak intensity by five and two times for the ground and first excited states, respectively.
Single photon emission from an InGaAs quantum dot precisely positioned on a nanoplane
(2007-02-12)
Hsieh, Tung-Po
;
Chyi, Jen-Inn
;
Chang, Hsiang-Szu
;
Chen, Wen-Yen
;
Hsu, Tzu Min
This work demonstrates single photon emissions from a site-controlled quantum dot (QD) grown on a self-constructed nanoplane. The size of the nanoplane on the micron-sized multifacet structure is accurately controlled by a low surface reducing rate (similar to 16 nm/min). Single QD spectral lines were resolved and identified. The antibunching behavior reveals that single photons are emitted from the positioned QD. (c) 2007 American Institute of Physics.